1. Technical Field
The present invention relates to a sensor device, and in particular, a sensor device which is preferable in a case where a detection direction of a detection axis of a sensor element that detects an angular velocity and acceleration is tilted.
2. Related Art
In navigation systems installed in a vehicle such as an automobile, an angular difference may be produced between a mounting surface of a substrate of an electronic apparatus and a detection direction of a detection axis of a sensor element mounted on a sensor device to be mounted on the substrate. In this case, the angular difference has an affect on angular velocities and signals of acceleration, appearing as a decrease in detection sensitivity and a detection error. Conventionally, software corrects such influence of the angular difference. However, a large angular difference between the detection axis and the actual rotation axis or that between the detection axis and a direction to which the acceleration to be added exceeds the correctable range of the software. This makes it difficult to detect the angular velocity and the acceleration.
In view of such a problem, a sensor device has been proposed in which the detection axis corresponds to the detection axis of the angular velocity and the acceleration by changing the mounting angle of the sensor device with respect to the mounting substrate.
JP-A-2008-96420 is a first example of related art. For example, in the first example, the inventor has proposed a sensor device that includes mounting leads formed by being folded so as to maintain a tilted state of a sensor component, into which a sensor element is built, with respect to the mounting substrate, and the sensor component mounted on the mounting leads is covered by a resin. The sensor device having such a configuration allows suppressing the decrease in detection sensitivity and the detection error caused by the angular difference.
JP-A-2008-51629 is a second example of related art. In the second example, a sensor device capable of multi-axis detection is disclosed. The second example shows a technique for changing the detection direction of the detection axis of the sensor element by fixing the side surface of the sensor device, into which the sensor element is built, to a base substrate. With this configuration, it is possible to turn the mounting angle of the sensor device by 90°. As a result, it is possible to detect the angular velocity and the acceleration that cannot be detected by a sensor element mounted parallel to the base substrate.
According to the sensor device disclosed in the first example, the detection axis of the sensor element can be tilted while achieving the mounting stability of the sensor device. Therefore, it is possible to reduce the risk that the detection error between the detection direction of the angular velocity and the acceleration and the actual angle exceeds the correctable range of the software. However, in the sensor device disclosed in the first example, the mounting angle of the sensor element is determined by a bending condition of the mounting leads, so that a variation in the mounting angle of the sensor element may cause a variation in the bending angle of the mounting leads. In addition, when the tilt angle of the sensor element is increased, the mounting leads are exposed to the top of a resin part. This makes it difficult to handle the sensor device in transferring such as chucking.
The technique disclosed in the second example cannot meet particular requirements of the mounting angle since there are only two choices (0° or 90°) for the mounting angle of the sensor element. Further, it is required to design and manufacture a dedicated base substrate for the relocation of wiring, causing an increase of the manufacturing cost.
Further, it is necessary to provide a test-write terminal to the sensor device for testing the sensor element and the like at the time of manufacturing or for writing data into an IC that controls the sensor element. However, in a case where the test-write terminal has the same configuration as that of the mounting terminal, the test-write terminal may be short-circuited by the inadvertent contact with other electrodes, electronic components, and the like.